1. Field of the Invention
The present invention relates to a cooling device for electronic parts of a vehicle, and it is preferably applicable to an electronic element mounted in an engine room of a vehicle.
2. Description of Related Art
One type of known cooling device for electronic parts is disclosed in JP-A-9-207691. The cooling device disclosed in JP-A-9-207691 has a housing box (an electrobox) including a double structure of an inner box portion and an outer box portion. An electronic control unit (an electronic control circuit) is housed in the inner box portion, and cooling air is introduced to a cooling air passage between the inner box portion and the outer box portion to prevent the temperature increase of the electronic control unit.
According to the prior art, the cooling air is not introduced to the electronic control unit directly. Thus, even if the cooling air includes dust, water or the like, the electronic control unit is prevented from them.
However, the cooling performance of the above described prior art may not be sufficient because of the double structure of the housing box. In other words, the cooling air is not directly introduced to the electronic control unit, and such indirect cooling may not be enough to cool the electronic control unit.